Download The Discovery of the Cell

Life is Cellular
7.1
P. Smith
Bio CP
The Discovery of the Cell
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The invention of the microscope in
the 1600s enabled researchers to
see cells for the first time.
Robert Hooke named the empty
chambers he observed in cork
“cells.”
Robert Hooke’s Microscope
The Discovery of the Cell

Robert Hooke
Robert Hooke’s Microscope
The Discovery of the Cell
Anton van Leeuwenhoek
was the first to observe
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living microorganisms.
Anton van Leeuwenhoek
The Discovery of the Cell
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Matthias Schleiden:
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1837 - all plants are
composed of cells.
The Discovery of the Cell
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Theodor Schwann
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1837 - all animals are
composed of cells.
The Discovery of the Cell
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Rudolf Virchow
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1858 - All living cells
are derived from
previously existing cells
The Discovery of the Cell
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Discoveries by German scientists Schleiden,
Schwann, and Virchow led to the development of
the cell theory.
The Cell Theory
All living things are made of cells.
Cells are the basic units of structure and function in
living things.
New cells are produced from existing cells.
Exploring the Cell

Scientists use light
microscopes and
electron microscopes to
explore the structure of
cells.

Compound light
microscopes have
lenses that focus light.
They magnify objects
by up to 1000 times.
Compound Light Microscope
Exploring the Cell

Chemical stains and
fluorescent dyes make
cell structures easier to
see.
Exploring the Cell

Transmission Electron
Microscope (TEM)
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Uses beams of electrons
to examine thin slices of
material
Provides twodimensional images of
cell structures
Exploring the Cell

Transmission Electron
Microscope (TEM)
Pollen grains
HIV Virus
Exploring the Cell

Scanning Electron
Microscope (SEM)

Uses beams of
electrons to view
the surface of a
specimen
Provides threedimensional
images of cells

Exploring the Cell

Scanning Electron
Microscope (SEM)

Scientists use
computers to add
color to electron
micrographs, which
are photos of objects
seen through a
microscope.
Prokaryotes and Eukaryotes
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Cells come in an amazing variety of shapes and sizes, but all
cells contain DNA.
All cells are surrounded by a thin flexible barrier called a cell
membrane.
There are two basic categories of cells based on whether they
contain a nucleus.

The nucleus (plural: nuclei) is a large membrane-enclosed
structure that contains DNA.

Eukaryotes are cells that enclose their DNA in nuclei.
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Prokaryotes are cells that do not enclose their DNA in nuclei.
Prokaryotes

Prokaryotes
are cells that do
not enclose
their DNA in
nuclei.

Bacteria
Eukaryotes

Eukaryotes are
cells that
enclose their
DNA in nuclei.

Animal Cells
Eukaryotes

Eukaryotes are
cells that
enclose their
DNA in nuclei.

Plant Cells
Eukaryotes


Eukaryotes are
cells that
enclose their
DNA in nuclei.
Protists
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Paramecium
Amoeba
Eukaryotes

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Eukaryotes are
cells that
enclose their
DNA in nuclei.
Fungi